Q1. I have no POS, can I sell e-books?
No POS? That will limit your options, but not cut you out of the game. The real question is probably, do you have ecommerce capability? Even that might not be a show stopper. There are options for stores that will allow you to sell ebooks online, where there is no need to integrate to an in-store POS or an existing ecommerce system. For example, you could work with the ABA's Indie Commerce solution or NACSCORP's My Books & More program with Baker & Taylor. These solutions are really tailored for smaller stores without an extensive ecommerce or POS capability. B&N, Follett, MBS, and others all have virtual bookstore options that can sell e-books online as well.
Q2. What percent of a title is usually sold as an e-book?
That can vary greatly, depending on a variety of factors, such as: (a) the title; (b) the faculty member; (c) how the store educates the student about the purchase decision; (d) the price; (e) availability of other options (e.g., number of used books, rental option, etc.); (f) demographic profile of your students; (g) DRM applied to the text; and the list goes on.
All of that being said, average sell-though right now looks like about 2-3%. We have seen a number of examples well over 30%, and even a few over 90%, but those are still more of the exception. E-book title availability is mostly within the large adoptions, and we did hear from a few schools this semester where the faculty member switched to an open source textbook for a large adoption, thus having big pick-up in digital adoption and subsequent impact on sales. This dynamic should be considered in your contingency planning processes and is likely to increase in the coming years with the current emphasis and funding for open source textbooks.